Vapor expelling pump



March 1, 1949. R. R. cuR-rls VAPOR EXPELLING PUMP s sheets-sheet 1 Filed Oct. 19, 1944 IIIIII .EN D Russell R. Curtis March l, 1949. R. R. cuRTls VAPOR EXPELLING PUMP 3 Sheets-Sheet 2 Filed Oct. 19, 1944 March 1, 1949. R. R. cuR'rls 2,463,251

VAPOR EXPELLING PUMP Filed oct. '19 1944 :s sheets-sheet 3 Russell R.Gwz`s d/1% Mffi Patented Mor. 1, 1949 VAPOR EXPELLING PUMP Russell R. Curtis, Dayton, (lhio, assignor to Cur- I tls Pump Company, Dayton, Ohio, a corporation of Ohio Apprcmon october 1s, 1944,'sma1 No. 559,432

11 claims. (ci. 10s-11s) This invention relates to devices for separating gases and vapors from liquids.

Particularly, the invention relates to booster pumps for aircraft fuel systems which efficiently separate gaseous materials from liquid fuel so that the fuel pumped to the fuel line will be in fully liquid condition, thereby avoiding a vapor lock in the fuel system.

' In accordance with this invention pumps are equipped with vents for liberation of gaseous material. The vents are so arranged that the gaseous material cannot commingle with the liquid material being pumped. An eicient trapping oif and venting of gaseous material is thereby maintained.

The invention will hereinafter be specifically described as embodied in booster pumps for airplane fuel systems. These pumps are suspended on or submerged in airplane fuel tanks. It should be understood, however, that the invention is not limited for such usage since the vapor and liquid-separating devices of the invention have general usage in the art.

A feature of the invention deals with the provision of collecting chambers for gas and vaporrich liquid stripped from fully liquid materia being pumped.

Another feature of the invention deals with the agitation of liquid being pumped and the immediate separation of the agitated liquid into separate chambers.

An object of the invention is to provide a booster pump for aircraft fuel systems which elliciently separates gases and vapor from liquid fuel being pumped from a fuel tank and simultaneously collects the vapor and gas-rich fuel in4 a separate chamber vented to the interior of the fuel tank at a point remote from the inlet of the pump.

A still further object of the invention is to equip aircraft booster pumps with vented chambers for receiving gas and vapor-rich liquid to deliver this liquid back to the source of liquid at a point remote from the inlet to the pump.

A further object of the invention is to provide vapor and liquid-separating devices vhaving chambers for receiving separated vapor-richY liquid and for discharging this liquid in such a manner that it will not commingle with the incoming liquid to the devices without first discharging the vapors and gases.

A still further objectof the invention is to provide liquid and vapor-separating pumps which agitate the incoming liquid to beat out bubbles of gas and vapor therefrom and collect the beaten-out bubbles of gas and vapor in chambers which are vented to the source of liquid at points remote from the inlet to the pump.

Other and further objects of the invention will be apparent to those skilled in the art from the following detailed description of the vannexed sheets of drawings which, by way of preferred examples, illustrate three embodiments of the invention.

On the drawings:

Figure 1 is a vbroken fragmentary vertical cross-sectional view, with parts in elevation, of an external booster pump and fuel tank assembly.

Figure 2 is a plan view of the vented chamberdefining cap for the pump of Figure l.

Figure 3 is a broken fragmentary vertical cross-sectional view, with parts in side elevation, of another form of external booster pump according to this invention mounted .on a fuel tank.

Figure 4 is an enlarged horizontal cross-sectional view, with parts in plan, taken substantially along the line IV-IV of Figure 3.

Figure 5 is a broken fragmentary vertical crssectional view of a submerged type of booster pump according to this invention mounted in a fuel tank.

Figure 6 is a horizontal cross-sectional view, with parts in plan, taken along the line VI-VI of Figure 5.

Figure 7 is a horizontal cross-sectional view, with parts in plan, taken along the line VII- VII of Figure 5.

As shown on the drawings:

In Figure 1 the reference numeral I0 designates generally an airplane fuel tank having a top wall Illa with a. vent I I therein and a bottom wall illb with an aperture I2 therethrough. The tank lll contains a pond P of liquid fuel having a top level L beneath the vent II.v

A booster pump and motor unit I3 according to this invention is mounted on the bottom wall Illb of thetank I0. The unit I3 includes a motor casing I4 with an end cap I5 having a hollow neck portion I5a, a pump casing portion ISb dening a volute chamber I6, and an outturned mounting flange I5c. The mounting flange underlies the tank wall IIlb and receives cap screws I'l therethrough which are threaded into a mounting ring I8 mounted inside the tank on the tank wall Inb to secure the unit I3 in depending relation onto the bottom wall Ib of. the tank I0. The mounting ring I8 surrounds the opening I2 in the bottom wall IIlb. A gasket I9 is'interposed between the flange |5c and the wall Illb to prevent leakage.

The casing portion Ib denes an open-topped volute chamber I6 and a ring 20 is mounted on the casing part to extend over the top of the volute chamber. The ring has a central aperture 20a. 3

A casing 2| is mounted on top of the ring 20 and has aperipheral skirt or side wall 2|a bottomed on thevring 2D. ,Cap screws 22 extend throughv the casing 2| and ring 20 into threaded relation in wells |5d of the casing I5.

The casing 2| has a top wall 2 Ib and a converging inner wall 2| c extending from the inner end of the top Wall 2|b to a circular rim 2|d tting freely within the aperture 20a of the ring 20. lThe inner wall 2 Ic denes a converging inlet mouth to the pump.

A chamber 23 is thus provided by the casing 2| above the ring 20 and around the inlet mouth of the pump. This chamber 23 is vented to the interior of the tank through a tube or pipe 24. The pipe or tube 24 extends upwardly in thepond P forv a sumcient distance to discharge out of its open top away from the downwardly flowing stream tothe inlet mouth of the pump.

The motor in the casing I4 'has a shaft 25l ex- A centrifugal impeller 26 is secured tothe l threaded end 25a of the shaft 25 and has a disk portion 26a bridging the interior of the neck pa'rt The bubble-rich fuel is directed back to the interior of the tank at a point remote from the inlet of the pump where the bubbles will rise in the pond to discharge their gases and vapors while the fully liquid material will be pumped through the volute chamber and out of the Pump- .Y

In the embodiment of theinventionshown in Figures 3 and 4, a pump 30 is mounted on the' bottom wall Illb of the' tank I0 in the same manner as the pump I3. Thus the pump 30 has a shaft well-dening portion 3| of a casing with an outturned mounted flange 3Ia receiving the cap screws, I1 therethrough which are threaded into the mounting ring I8 for suspending the unit on the bottom wall of the tank.

superimposed rings 32 and 33 are mounted on the flange part 3Ia and project through the opening I2 ofthe tank into the interior of the tank. The ring 33 receives a plurality of upstanding spacer tubes 34 on the top thereof on which is mounted a guide shield '35; Bolts 36 extend through the shield 35, the tubes 34, and'r both rings 33 and 32 into threaded engagement in wells 3|l of the mounting ange 3Ia.

The ring 32 has a plurality of radial slots 32a therearound connecting the interior of the ring with the pond P. The ring 32 also has a top shoulder 32h for a purpose to be hereinafter described.

'I'he ring 33 defines an annular pumping chamber 33a discharging into a tube 31 extending I 5a and extending into the volute chamber I6.

Curved upstanding pumping vanes 2Gb are provided on the disk portion 26a and radiate outwardly from the central portion thereof. The vanes have close-running clearance with the ring 20 and have inner end portions freely exposed to the inlet mouth of the pump together with outer end portions discharginginto the volute chamber I6. A

'I'he inner end portions of the vanes agitate liquid fuel owing through the inlet mouth of the pump'and beat out bubbles of gas and vapor from The-rim 2|d of the casing is spaced radially inward from the wall defining the aperture 20a of the ring 20 and an annular' gap 21 connects the inner ends of the pumping channels between the vanes 2Gb with the chamber 23. Bubbles B liberated by the pumping vanes 26h, being lighter than the liquid material, will rise through the gap 21 to be collected in the chamber 23. The chamber 23 is thus lled with bubble-rich liquid, the bubbles of which can rise through the tube 24 into a portion of the pond P which is remote from the inlet mouth to the pump. The bubbles will then rise through the remaining portion of the pond to burst at the surface thereof and discharge their gases and vapors to the outlet vent II. In the event that the level L of the pond P falls below the top of the tube 24, the bubbles, of course, will discharge directly from the top of the tube into the atmosphere above the pond.

The pumping vanes 26h effect somewhat of a circulation of bubble-rich liquid through the chamber 23andV tube 24.

I'he pump unit I3 of this invention therefore eciently separates fully liquid fuel and bubblethe fuel. Only fully liquid fuel is'discharged by l through the pond P and through the top wall Illa of the tank. t

The ring 33 has an upper portion 33h defining a converging mouth 31. The guide shield 35 has -duced-diameter portion of the shaft 38 and is bottomed on a washer 40 disposed on a shoulder of theshaft at the ends of the reduced-diameter pgrtion. A nut 4I clamps the hub on the washer The impeller 39 has a radial disk portion 39a bridging the aperture of the ring 32 about level with the bottom of the slots 32a. i Y L A hollow inverted frusta-conical portion 39h extends from the top of the hub 39 into the ring 33 and has an out-turned multi-apertured ange 39e at the upper end thereof. This ange 39e has a depending skirt 39d'provided with an outturned flange 39e. A sealing ring 42 rof graphitic carbon or the like is disposed around the skirt 39d to have a slip fit thereon and is bottomed on the ange 39e to form a floating seal. The sealing ring also has a slip fit on the shoulder 32h and separates the pumping chamber 33a from the interior of the ring 32.

Curved pumping vanes 43 are mounted on the outturned flange 39e of the hub and have inner upper end portions 43a aligned with the mouth 31 together with radially extending outer end portions 43h extending under the ring portion 33h and communicating with the pumping chamber 33a. The vanes also .have depending portions 43c aligned with the apertures 44 in the flange 39o.

The shield 35 has an inclined deecting skirt portion 35h which cooperates with the portion 35a to direct fuel from the pond P into the pump. I'his fuel is received by' the inner ends of the pumping vanes 43. The fuel is thus agitated and bubble-rich liquid is acted on by the vane portions 43a to rise through the mouth 31 around the portion 35a of the shield and under the portion 35h of the shield. The bubbles, being lighter than the liquid of the pond, tend to rise in the pond and will hug the under face of the shield until they reach the periphery, whereupon they will rise through the pond to the top level L thereof and burst to discharge the gases and vapors through the tank vent l I.

The vane portions 43e serve to direct bubblerich liquid through the apertures 44 around the conical portion 39h01' the impeller and into the ring 32. This bubble-rich liquid discharges through the slots 32a of the ring back to the interior of the tank. The bubbles, of course, will rise around the ring 33 to be deflected by the portion 35h of the shield and merge with the stream of bubbles from the mouth 31.

The impeller 39 has the vanes 43 thereof arranged outwardly from its axis of rotationand an open-ended channel is provided along the inner ends of the blades. Thus, the inner ends of the blades communicate with the mouth 31 and with the holes 44. Both the mouth 31 and the holes 44 communicate back to the pond.

The fully liquid material, being heavier 4than the gas and vapor-rich material, is thrown by centrifugal force of the outer ends 43h of the blades into the pumping chambe;` 33a, from which it is discharged through the tube 31.

As shown in Figure 4 the holes 44 through the impeller flange portion 39c are preferably in the form of elongated slots.

The pump 30 thus receives liquid through the guide shield 35 and the inner ends of the Dumping varies 43 agitate this fuel to release streams of bubble-rich liquid through the mouth 31 and the holes or slots 44. Both the mouth 31 and the holes communicate back with the interior of the pond and the bubble-rich liquid is allowed to rise in the pond under the deector portion of the shield to the periphery thereof, whereupon it will rise to the surface of the pond P. 'I'he shield 35 has a suiciently large periphery so that the bubble-rich liquid will be remote from the incoming liquid.

The pump 30 diiers from the pump I3 in providing an arrangement whereby bubble-rich liquid can ilow upwardly back to the pond of fuel as well as downwardly through a chamber communicating with the pond of fuel.

In the embodiment shown in Figures 5 to 7, a

pump and motor unit 50 is submerged in the tank I0. The unit 50 includes a base plate 5I bridging the aperture I2 of the bottom tank wall Illb. The base 5I has a downwardly sloping portion pitched to a threaded boss portion 5Ia receiving a plug 52 in threaded relation therein. A circular boss 5Ib depends from the base 5| adjacent the pitched portion thereof and a at mounting ange portion 5Ic underlies the tank wall IIlb to receive the mounting screws I1 therethrough. The mounting ring I8 is mounted on the bottom wall of the tank for receiving the screws I1 in threaded relation therein.

A sump Sis created by the sloping portion of the base within the ring I B.

A plate 53 extends across the sump portion in spaced relation thereabove and has a plurality tion 5I together with a tubular portion 53h extending into the boss 5Ib. The plate 53 is thus held in spaced relation from the plate 5I and has a central aperture thereinY providing an inlet opening O at the bottom of the pump.

The plate 53 receives a plate 54 on the top thereof which is curved to cooperate therewith for providing an annular chamber around the inlet opening O. This chamber 55 is connected with the inlet opening O through a gap 5B.

The plate 54 has a tubular section 54a mounted on top of the tubular portion 53h.

A third plate 51 is mounted on top of the plate 54 and cooperates therewith to define an annular chamber 58. The plate 51 has a tubular portion 51a mounted on top of the portion 54a. A passageway 55 connects the chamber 58 with the interior'of the tubular portion 51a.

Another plate il is mounted on top of the plate 51 and cooperates therewith to define an annular chamber il. The plate il has a tubular portion Gla mounted on the top of the portion 51a.

The plate 5I! has a converging central aperture defining a top opening 0' to the pump.

The intermediate plates 51 and 54 havecurved- The two diverging lips 54h and -51b cooperate to dene a gap or inlet- 64 connecting the central passage with the chamber 5l.

The chambers 55 and 8i discharge into a passage 65 provided by the plates. This passage 65 has an arcuate contour as shown in Figures 6 and 7 and as shown is continued by a leg portion h of the plate 6B to a level materially above the top inlet opening 0'. The leg portion 60h can be omitted if desired by having the passage discharge at any point relatively remote from the inlets O and O' to prevent the bubbles from being entrained in the iuid flowing to the inlets.

A motor mounting base 66 including a collar portion 65d surrounding the tubular portion 60a of the pate 63 and a ring portion 66h surrounding a neck 60e of the plate 60 has an arm BSc between the ring and collar portions extending upwardly to a motor casing S1. Screws such as 53 are provided at intervals around the neck 60e and are passed through holes in plate 50 into threaded engagement with the ring portion 66h of the base G5.

A motor shaft 6! depends from the casing 61 and carries an impeller 1l thereon. The impeller III has a hub 1I keyed onto the shaft 69. This hub 1I ilares outwardly as at 1Ia at a level opposite the opening 64 to the chamber 58. Yanes 12 are mounted in spaced relationship around the flaring portion 1Ia. These blades 12 have inner end portions terminating adjacent the bottom plate 53 and the top pate 5l to communicate with the gaps 55 and 53. The vanes have central portions extending into the gap 64.

A nose piece or nut 13 is threaded on the shaft 69 to lock the hub 1I on the shaft against a shoulder provided on the shaft.

Fuel from the pond P can ow into either end of the pump through the inlets O and O. The blades 12 will agitata the fuel to discharge bubblerich streams into the annular chambers 55 and BI. sage 55`vback to the interior of the tank. The

of depending legs 53a bottomed on the base por- 1l fully liquid material, however, is impelled by the These chambers discharge through the pas- 7 vanes 12 into the chamber 58 and through the passageway 59 into a discharge passageway14 provided by the superimposed nested tubular sec- .tions 53h, 54a, 51a and 50a.

An end cap 15 forms a closure for the bottom of the passageway 14 and a discharge nipplel16 communicates with the top of the passageway 14. The nipple 16 is connected .to a pipe line (not shown).

A bolt 11 extends through thenipple 16 and through the passage 14 into threaded relation in the cap 15 to draw the cap and nipple together,

thereby holding all of the superimposed tubular section parts in posi-tion and also securing these parts to the baseplate 5I.

charge passageway communicating with a pipe line.

The superimposed plates are held together `by the plates and legs 53a and threaded into bosses 5Id of the base plate. l

The various forms of pumps illustrated on the drawings thus have vapor-receiving chambers coacting with pump impellers to receive vaporrich liquid liberated by the impellers and to direct this liquid back to the source of liquid at points remote from the pump inlet so that the vapors in the`bubblerich liquid can be liberated. Repeated circulation of liquid through the pump will result in production of a stabilized liquid,

It will, of course, ,be understood that various details of construction may be varied through a wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by thelscope of the appended claims. Y l 1 I claim as my invention: I

1. A vapor expelling pump comprising a casing .impeller for pumping liquid directly from the chamber, and said casinghaving .a1condut astank through said `pumping chamber, vanes disposed on said impeller'adjacent the inlet of said pumping chamber for concurrently liberating bubble-rich liquid from fully liquid material being pumped, a casingin said tank mounted on said pump deiining an annular chamberv and a central inlet mouth for said pummsaid inlet mouth of said casing terminating adjacent said impeller and cooperating with the pump structure to provide an annular opening around the inlet mouth communicating with said annular-chaniberV to direct bubble-rich liquid from said impeller vanes into said annular -chamber to prevent passage of said bubble-rich liquid through said pumping scciated therewith extending intoj-the tank to a -a-poi'ntremote from theA inlet mouth loi?l thel pump .3c the bolt 11 and also by bolts 18 extending through dening an annular pumping chamber having a'- central passageway therethrough, means cooperating with said casing defining ow paths on opposite sides of said pumping chamber, apump impeller in said central passageway having pumping vanes for discharging bubble-rich liquid into ing the pump inlet.

whereby bubble-rich liquid dischargedfrom said conduit will not be commingled with liquid enter- 4.- A vapor expelling devicel comprising a casing having a central passageway therethrough and an annular chamber around said central passageway communicating with the central passageway, a shield on `said casing extending into said central passageway and cooperating with the casing to provide an annular passage, said shield having a deflecting wall overlying the casing and radiatingV from said annular passage, a pump impeller in said central passageway having an outturned flange with slots at spaced intervals therearound, upstanding vanes mounted on said outturned flange of the impeller and extending into said annular chamber, and said upstanding vanes including portions aligned with and intermediate said slots andr said annular passage for directing streams of bubble-rich liquid concurrently through the slots and annular passage for discharge under the deflecting portion of the shield.

5. In combination, a tank having an apertured bottom wall, avpump mounted on said botsaid ow pathsk together with vanes for dischargy ing bubble-freed liquid into said annular pumping chamber, and means for directing bubble-rich liquid from said ow paths away from said central passageway.

2. A vapor expelling pump comprising a casing dening an annular pumping chamber and: a

central passageway therethrough, said annular pumping chamber having an annular inlet communicating with said central passageway' and a tom walloi the tank having a portion closing the aperture therein, a casing ring on said'pump projecting through said aperture into said tank and having a central passageway and a pumping chamber around said passageway communicating'therewith, said casing ring having a conduit connecting the lower portion of the central passageway with the interior of the tank, a shield mounted on the top of said' casing ring having a central mouth-defining portion providing'an inlet mouth to the top of the central passage, said A shield being' spaced from vsaid casing ring to cooperate with the top portion of the casing ring for deiining an annular flow path, and an impeller rotatably mounted in said casingring having pumping vanes for-discharging liquid material through said pumping chamber together with agitating vanes for discharging bubble-rich liquid concurrently throughY said annular ilow path and through said conduit of the casing ring, and said guide shield havinga de'flecting wall radiating outwardly from said inlet mouth re- 9 ceiving the bubble-rich liquid thereunder to deiiect the liquid away from the inlet mouth.

6. A vapor expelling pump comprising an annular casing defining an open-ended central fluid inlet passageway, a central annular pumping chamber communicating with said passageway intermediate the ends thereof, and annular bubble-receiving chambers on opposite sides of said pumping chamber surrounding and communieating with said central passageway, and an impeller rotatably mounted in said central passageway having vanes associated therewith for discharging fully liquid material into said pumping chamber and for concurrently discharging bubble-rich liquid into said chambers on opposite sides of the pumping chamber to prevent passage of said bubble-rich liquid into said pumping chamber.

'7. A vapor expelling pump comprising a casing having a central fluid inlet passage therethrough and three superimposed annular chambers therein surrounding and communicating with said central passage, means defining a common discharge conduit for the outer chambers, means denning a separate discharge conduit for the central chamber, and a pump impeller rotatably mounted in said central passage having vanes associated therewith for discharging fully liquid material through the central chamber and for concurrently discharging bubble-rich liquid throughv the outer chambers into said common outlet.

8. A submerged pump and motor unit comprising a base plate for securing the unit to a tank wall in submerged relation in the tank, a casing carried by said base plate in spaced relation therefrom having an open-ended central passageway and three annular chambers in superimposed relation surrounding said central passageway and in communication therewith, said casing having a discharge conduit communicating with the outer chambers, said casing having a second discharge conduit communicating with the middle chamber, a motor shaft extending into said central passageway, an impeller on said motor shaft in said central passageway, and vanes on said impeller arranged relative to said chamber for discharging fully liquid material through the middle chamber into said second conduit and for concurrently discharging bubble-rich liquid through the outer chambers into said first mentioned common discharge conduit.

9. In combination, a tank having an apertured bottom wall, a base plate mounted on said bottom wall closing the aperture thereof, an upstanding tubular leg on said base plate having a discharge passage therethrough, a casing associated with said leg defining an open-ended passageway communicating with the interior of the tank at lboth ends thereof, said casing having three annular chambers around said open-ended passageway in communication therewith, the middle of said chambers communicating with the passage in said upstanding leg, means on said casing providing a discharge outlet for the outer chambers communicating with the interior of the tank in spaced relation from the passageway, and a pump impeller rotatably mounted in said passageway having vanes associated therewith for pumping liquid material through the middle chamber and bubblerich liquid through the outer chambers. 10. A vapor expelling pump comprising a casing defining an annular pumping chamber and a central passageway therethrough, said annularv pumping chamber having an annular inlet communicating with said central passageway and a peripheral outlet, means coacting with said casing on opposite sides of said pumping chamber to define iiow paths isolated from said pumping chamber, a centrifugal impeller rotatable in said central passageway, said impeller having vanes thereon with inner ends projecting into said central passageway to agitate the liquid to create a stream of bubble-rich liquid and with outer ends projecting into said annular inlet to pump bubblefree liquid from the central passageway through said annular inlet into the pumping chamber and then into the said peripheral outlet, the inlets of said flow paths being disposed adjacent said inner vane ends and respectively on opposite sides thereof to receive said bubble-rich stream of liquid, and means guiding the bubble-rich stream from said flow paths to discharge the bubbles in spaced relation from said central passageway.

11. A vapor expelling pump comprising an annular casing defining an open ended central fluid linlet passageway, a central annular pumping u into said pumping chamber.

chamber communicating with said passageway intermediate the ends thereof, and annular bubble-receiving chambers respectively disposed on opposite sides of said pumping chamber surrounding and communicating with said central passageway, and a centrifugal impeller rotatably mounted in said' central passageway, said impeller having vanes thereon with inner ends projecting into said central passageway to agitate the liquid to create a stream of bubble-rich liquid for discharge into said bubble-receiving chamber and with outer ends projecting into said annular pumping chamber to concurrently pump bubble-free liquid from said central passageway RUSSELL R. CURTIS.

REFERENCES CITED The following referencesare of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,150,686 Leblanc Aug. 17, 1915 1,345,895 Seguin July 6, 1920 1,803,885 Adams May 5, 1931 2,306,298 Curtis Dec. 22, 1942 2,370,778 Compton Mar. 6, 1945 2,388,939 Stepanoif Nov. 13, 1945 FOREIGN PATENTS Number Country Date 630.932 Germany June 9. 1936 

